REVIEWED: Remove some `const` from text buffer return values

Lately got some compilation `errors` related, it seems GCC 14 interprets some `const`-missmatch as errors instead of warnings (as previous versions).

But in any case, I don't see why an user won't be able to operate directly over of those returned buffers; `const` adds a restriction (for security reasons?) that in my opinion is useless.

From an expert on compilers (w64devkit creator), here there are some notes I agree with:

```
No const. It serves no practical role in optimization, and I cannot recall an instance where it caught, or would have caught, a mistake. I held out for awhile as prototype documentation, but on reflection I found that good parameter names were sufficient. Dropping const has made me noticeably more productive by reducing cognitive load and eliminating visual clutter. I now believe its inclusion in C was a costly mistake.

(One small exception: I still like it as a hint to place static tables in read-only memory closer to the code. I’ll cast away the const if needed. This is only of minor importance.)
```

Ref: https://nullprogram.com/blog/2023/10/08/

src/raylib.h

@@ -1510,15 +1510,15 @@ RLAPI const char *TextFormat(const char *text, ...);
 RLAPI const char *TextSubtext(const char *text, int position, int length);                  // Get a piece of a text string
 RLAPI char *TextReplace(const char *text, const char *replace, const char *by);             // Replace text string (WARNING: memory must be freed!)
 RLAPI char *TextInsert(const char *text, const char *insert, int position);                 // Insert text in a position (WARNING: memory must be freed!)
-RLAPI const char *TextJoin(const char **textList, int count, const char *delimiter);        // Join text strings with delimiter
-RLAPI const char **TextSplit(const char *text, char delimiter, int *count);                 // Split text into multiple strings
+RLAPI char *TextJoin(const char **textList, int count, const char *delimiter);              // Join text strings with delimiter
+RLAPI char **TextSplit(const char *text, char delimiter, int *count);                       // Split text into multiple strings
 RLAPI void TextAppend(char *text, const char *append, int *position);                       // Append text at specific position and move cursor!
 RLAPI int TextFindIndex(const char *text, const char *find);                                // Find first text occurrence within a string
-RLAPI const char *TextToUpper(const char *text);                                            // Get upper case version of provided string
-RLAPI const char *TextToLower(const char *text);                                            // Get lower case version of provided string
-RLAPI const char *TextToPascal(const char *text);                                           // Get Pascal case notation version of provided string
-RLAPI const char *TextToSnake(const char *text);                                            // Get Snake case notation version of provided string
-RLAPI const char *TextToCamel(const char *text);                                            // Get Camel case notation version of provided string
+RLAPI char *TextToUpper(const char *text);                                                  // Get upper case version of provided string
+RLAPI char *TextToLower(const char *text);                                                  // Get lower case version of provided string
+RLAPI char *TextToPascal(const char *text);                                                 // Get Pascal case notation version of provided string
+RLAPI char *TextToSnake(const char *text);                                                  // Get Snake case notation version of provided string
+RLAPI char *TextToCamel(const char *text);                                                  // Get Camel case notation version of provided string
 
 RLAPI int TextToInteger(const char *text);                                                  // Get integer value from text
 RLAPI float TextToFloat(const char *text);                                                  // Get float value from text

src/rtext.c

@@ -1629,7 +1629,7 @@ char *TextInsert(const char *text, const char *insert, int position)
 
 // Join text strings with delimiter
 // REQUIRES: memset(), memcpy()
-const char *TextJoin(const char **textList, int count, const char *delimiter)
+char *TextJoin(const char **textList, int count, const char *delimiter)
 {
     static char buffer[MAX_TEXT_BUFFER_LENGTH] = { 0 };
     memset(buffer, 0, MAX_TEXT_BUFFER_LENGTH);
@@ -1663,7 +1663,7 @@ const char *TextJoin(const char **textList, int count, const char *delimiter)
 
 // Split string into multiple strings
 // REQUIRES: memset()
-const char **TextSplit(const char *text, char delimiter, int *count)
+char **TextSplit(const char *text, char delimiter, int *count)
 {
     // NOTE: Current implementation returns a copy of the provided string with '\0' (string end delimiter)
     // inserted between strings defined by "delimiter" parameter. No memory is dynamically allocated,
@@ -1671,7 +1671,7 @@ const char **TextSplit(const char *text, char delimiter, int *count)
     //      1. Maximum number of possible split strings is set by MAX_TEXTSPLIT_COUNT
     //      2. Maximum size of text to split is MAX_TEXT_BUFFER_LENGTH
 
-    static const char *result[MAX_TEXTSPLIT_COUNT] = { NULL };
+    static char *result[MAX_TEXTSPLIT_COUNT] = { NULL };
     static char buffer[MAX_TEXT_BUFFER_LENGTH] = { 0 };
     memset(buffer, 0, MAX_TEXT_BUFFER_LENGTH);
 
@@ -1727,7 +1727,7 @@ int TextFindIndex(const char *text, const char *find)
 // Get upper case version of provided string
 // WARNING: Limited functionality, only basic characters set
 // TODO: Support UTF-8 diacritics to upper-case, check codepoints
-const char *TextToUpper(const char *text)
+char *TextToUpper(const char *text)
 {
     static char buffer[MAX_TEXT_BUFFER_LENGTH] = { 0 };
     memset(buffer, 0, MAX_TEXT_BUFFER_LENGTH);
@@ -1746,7 +1746,7 @@ const char *TextToUpper(const char *text)
 
 // Get lower case version of provided string
 // WARNING: Limited functionality, only basic characters set
-const char *TextToLower(const char *text)
+char *TextToLower(const char *text)
 {
     static char buffer[MAX_TEXT_BUFFER_LENGTH] = { 0 };
     memset(buffer, 0, MAX_TEXT_BUFFER_LENGTH);
@@ -1765,7 +1765,7 @@ const char *TextToLower(const char *text)
 
 // Get Pascal case notation version of provided string
 // WARNING: Limited functionality, only basic characters set
-const char *TextToPascal(const char *text)
+char *TextToPascal(const char *text)
 {
     static char buffer[MAX_TEXT_BUFFER_LENGTH] = { 0 };
     memset(buffer, 0, MAX_TEXT_BUFFER_LENGTH);
@@ -1793,7 +1793,7 @@ const char *TextToPascal(const char *text)
 
 // Get snake case notation version of provided string
 // WARNING: Limited functionality, only basic characters set
-const char *TextToSnake(const char *text)
+char *TextToSnake(const char *text)
 {
     static char buffer[MAX_TEXT_BUFFER_LENGTH] = {0};
     memset(buffer, 0, MAX_TEXT_BUFFER_LENGTH);
@@ -1821,7 +1821,7 @@ const char *TextToSnake(const char *text)
 
 // Get Camel case notation version of provided string
 // WARNING: Limited functionality, only basic characters set
-const char *TextToCamel(const char *text)
+char *TextToCamel(const char *text)
 {
     static char buffer[MAX_TEXT_BUFFER_LENGTH] = {0};
     memset(buffer, 0, MAX_TEXT_BUFFER_LENGTH);